The above-identified U.S. Patents describe a stamping and forming machine having first and second ram assemblies which are reciprocable towards and away from each other along horizontal paths of reciprocation. Strip material is fed along a strip feed path which extends between the ram assemblies and the ram assemblies have tooling on their ends for performing stamping and forming operations on the strip. The ram assemblies are reciprocated by oscillating levers to which they are coupled. The levers, in turn, are coupled to a central power shaft by eccentric assemblies.
The eccentric assemblies and the levers of the above-identified U.S. Patents are such that the ram assemblies have a fixed stroke. Most stamping presses have fixed, rather than adjustable, strokes and a fixed stroke machine is satisfactory for many stamping and forming operations. However, it would be desirable to provide a system for adjusting the strokes of the ram assemblies of the machines described in the above-identified patents. Assuming that the motor which rotates the power shaft of the machine has a fixed torque, an adjustable stroke system would permit the force exerted on the strip material to be varied by changing the stroke. The present invention is directed to improvements in stamping and forming machines which permit adjustment of the strokes of the machine for different stamping and forming operations.